Signaling system for drive-in theaters



Sept. 19, 1950 D. G. cHAKlRls 2,522,930

STGNALTNG SYSTEM EOE DRIVE-TN THEATERS Filed July 12, 1949 l2 A l.

., F Zr INVENTOR.

9 DEMETRIUS CHAKRIS Patented Sept. 19, 1950 SIGNALIN G SYSTEM FOR DRIVE-IN THEATERS Demetrius `Gf. Chakiris, Dayton, Ohio, assignor to Autocrat Inc., Dayton, Ohio, a corporation of Application July 12, 1949, Serial No. 104,358

12 Claims.

This invention relates to a, signaling system and more particularly to a signaling system of the type used in drive-in theaters and the like. It has been found that the patrons of drive-in theaters have their appetites greatly increased as they sit out in the openair watching a movie and that one of the large sources of income in a drive-in theater is obtained by selling peanuts, popcorn, pop, candy, et cetera to the patrons. However, the problem of finding out which patrons in an unlighted drive-in theater want service is a difficult one.

Various signaling arrangements have now gone into rather extensive use including the signaling arrangement shown and claimed in copending application Serial No. 74,802, filed February 5, 1949, of which I am one of the inventors. Various arrangements are shown in said copending application for supplying power for operating individual signal lights arranged throughout the parking area. The one arrangement utilizes power` from the amplifier system for energizing small neon signal lights. This system furnishes a flickering light which is operative at all times while sound waves are being supplied to the speaker system, but such lights do not function for short periods of time when there is silence. Another arrangement disclosedtherein contemplates the use of additional conductor means for supplying a separate source of power for operatf.

ing the signal lights. The need for such additional conductor means increases the cost of the wiring installation for any theater and in the case of theaters which have already been installed Without a signaling system, it practically necessitates a complete rewiring job which is almost prohibitive from a cost standpoint. It is an object of this invention to provide a signaling system which uses the existing speaker circuits for distributing unfailing power to the signals.

More particularly, it is an object of this invention to provide an arrangement in which a two wire system is used for distributing both direct current power for operating various signal and guide lights throughout the parking area as well as for distributing the output of the main vamplifier to the loud speakers disposed in the cars.

Other objects and advantages reside in the construction of parts, the combination thereof and the mode of operation, as will become more apparent from the following description.

In the drawings:

Figure 1 diagrammatically shows the circuit arrangement used for supplying direct current power and audio signals from a central point in an outdoor theater to the loud speaker stations located throughout the parking area; and

Figure 2 is a fragmentary circuit diagram showing circuit details used for signal lights of the incandescent type.

Referring now to the drawings wherein I have diagrammatically shown a preferred circuit arrangement, reference numerals Il) and I2 designate respectively the main amplifier and a source of pure direct current power and reference numeral I 4 designates a mixing unit wherein the audio signals and the direct current power are mixed and fed into the distribution lines tl 6 which lead from the mixing unit to the various loud speaker stations or junction boxes I8 located throughout the theater. The direct current power supply may be of any type such as the `well-known storage batteries, reotiers, etc. For

purposes of simplifying the circuit diagram, only one of the loud speaker stations has been shown,

whereas one speaker station would be provided for each pair of parking spaces in accordance with standard practice.

The mixing unit I 4 includes a blocking condenser 20 which serves to prevent the flow of direct current from the power supply source I2 to the power amplifier l0. An audio frequency choke 22 has been provided in the circuit, as shown, so as to prevent the flow of :audio signals from the amplifier to the direct current power supplying means I2. By virtue oi the above described arrangement, it is obvious that the conventional main power lines I 6 have supplied thereto both audio signals and direct current power so that each of the speaker stations I 8` is supplied with direct current power for operating various lights such as signal lights, guide lights, et cetera.

Each speaker station comprises a transformer having a primary coil 24 and a secondary coil 26. One or more speaker units 28 are connected in circuit with the secondary coil 2S so as to be energized thereby in accordance with standard practice. A blocking condenser 30 is provided in the connection from the main power line I6 to the primary coil 24 so as to prevent the flow of direct current power through the transformer. The usual safety limiting resistor 32 has been provided in the line leading to one side of the transformer coil `2li so las to prevent excessive flow of current to the transformer in the' event of a short-circuit in one of the speaker lines or the like. The loud speaker units 28 are connected to the secondary coil of the transformer through conventional plug and socket units designated by the reference numeral 34.

As indicated in Figure 1 of the drawings, three wires lead from each junction boX or speaker station to each speaker unit. Each speaker station serves the two cars which are parked on either side of the junction box. Neon signal lights 36 have been provided in the circuit, as shown, for giving signals when the occupants of one or the other of the cars parked next to the speaker station desire to attract the attention of a car hop. One light 36 is provided for each speaker or each car parked in the theater and each of the lights 36 is under control of-a switch 38 mounted on the adjacent speaker. These lights are preferably located on the junction box in which the transformer is located. The arrangement of the switch 38 is such that closing of the same places a direct short across the neon lamp and thereby extinguishes thelight.

Suitable limiting resistors 40 have been -provided in the neon lamp circuit so as to prevent excessive flow of current when the control switches 38 are closed. vIn some theaters guide lights, such as the light 42, are provided adjacent each speaker station. These lights remainon at all times when the theater is in use and serve the purpose of guidingl the patrons to the parking spaces provided adjacent the speaker stations. The guide lights 42 may be directly connected across the main power linespas shown, through a limiting resistor M. VFor purposes of illustration, I have shown a switch 46 in series with the guide light 42. The switch 4G maybe omitted in those installations whereit is desired to have the guide lights d2 show up at all times. The switch liti may be a manually operated switch or it may be a relay operated switch controlled from the operating booth. In some` installations it may be desired to use treadle switches mounted in the parking spaces which operate to shut off the guide light just as soon as the parking spaces adjacent the speaker station are occupied.

In Figure 2 of the drawings I have shown a slightly modied wiring diagram for use when incandescent lamps are substituted for the neon lamp shown in Figure l. As indicated in Figure 2 of the drawings, a choke coil 5B is provided in the power line leading to the incandescent lamp 52 so as to Drevent needless flow of audio signals to the signal lights 52. The signal lamps 52 are arranged in series circuit relationship with the control switches 54 so that in order to energize the lamps 52, it is necessary to close the switches 54. The guide light 5t, which corresponds to the guide light 42 of Figure 1, is connected in series circuit relationship with the switch 58 which in turn corresponds to the switch 46 of Figure l.

For a more detailed description of the physical construction of the junction boxes and the speakers, reference is hereby made to'savid copending application Serial No. 74,802.

Although the preferred embodiment of the device has been described, it will be understood that within the purview of this invention various changes may be made in the form, details, proportion and arrangement of parts, the combination thereof and mode of operation, which generally stated consist in a device capable of carrying out the objects set forth, as disclosed and of which comprises a transformer having a primary coil and a secondary coil, circuit means for connecting said primary coil to the outlet of said power amplier, a plurality of speakers, means for connecting at least one of said speakers to each of said secondary coils, a source of direct current power, means for connecting said direct current power to said circuit means including audio choke coils for preventing the flow of audio signals from said amplifier to said power source, blocking condenser means in said circuit means ahead of said ampliiier for preventing the ilow of direct current from said power source to said ampliner, blocking condenser means at each of said speaker stations for blocking the flow of direct current from the power source to said transformers, neon light means at said speaker stations connected to said circuit means so as to be energized by said direct current, and means for shcrt-circuiting said neon light means so as to render the same ineffective for lighting.

2. In a drive-in theater, an ampliner for audio signals, a plurality of loud speaker stations, each of which comprises a transformer having a primary coil and a secondary coil, circuit means for connecting said primary coil to the outlet of said power amp-liner, a lplurality of speakers, means for connecting at least one `of said speakers to each of said secondary coils, a source of direct current power, means for connecting said direct current power to said circuit means including audio choke coils for preventing the flow of audio signals from said amplifier to said power source, blocking condenser means in said circuit means ahead of said ampliner for preventing the flow of direct current from said power source to said amplifier, blocking condenser means at each of said speaker stations for blocking the ilow of direct current from the power source to said transformers, neon light means at said speaker stations connected to said circuit means so as to be energized by said direct current, and means for short-circuiting said neon light means so as to render the same ineffective for lighting, said last named means comprising circuit making and breaking means mounted on said speakers;

3. A signaling system for use in a drive-in theater wherein a pair `of conductors are provided for distributing audio signals from an amplier to loud speakers distributed throughout the theater comprising incom-bination, a source of direct current power, means for connecting said direct current power source to said conductors including audio chokes for preventing the iiow of audio signals fromsaidamplii'ler through said conductors to said source of direct current power, direct current blocking condenser means for blocking the ilow of direct current from said source to said speakers, light means distributed throughout said theater, and means for connecting said light means to said conductors. y

4. A signaling system for use in a drive-in theater wherein a pair of conductors are provided for distributing audio signals from an amplier to loud speakers distributed throughout the theater comprising in combination, a source of direct current power, means for connecting said direct current power source to said conductors including audio chokes for preventing the ilow of audio signals from said ampliiier through said conductors to said source of direct current power, ydirect current blocking condenser means for blocking the now of direct current from said source to said speakers, light means distributed throughoutsaid theater, and means for connecting said assenso light means to saidfcondu'ctors, said last named means includingaudio 'choke meansffor preventing the How of audio signals to said lightlmeans.

Ina drive-in theater, amplier means for audio signals, a plurality i of speakers, a two-wire distributing system for connecting said-Speakers tosaid amplifiermeans, a concession l.signal lightadjacent each4 of said speakers, a source of direct current power, i means `for connecting said source of `direct current power to said two-wire distributing system including audio choke means for preventing the flow ofaudio signalsfrom said two-wire distributing system to said power source, direct current blocking rcondenser means in said two-wire distributing systemfl for preventing the flowr'oi direct current from said power source to said amplier means, direct current `opi-:rated siga nal meanspand -means fonconnecting sai-d signal means to said two-wire 'distributing system.

, 6.1`In combination with a conventional drivein theater audio signal distributinglsystem whereina pair of conductors are vused' for `supplying audio signals from an amplifier to a plurality of speaker transformers distributed throughout the theater, light means distributed throughout the theater, a source of direct current power, means for connecting said source of direct current power to said distributing system including audio choke means for preventing the flow of audio signals from said system to said source of power, direct current blocking condenser means in said system between said source of power and said amplier for preventing the flow of power from said source to said amplifier, means for connecting said light means to said system including audio choke means for preventing the flow of audio signals to said light means, and direct current blocking condenser means connected in the circuit leading to each of said speaker transformers for blocking the now of direct current to the speakers.

7. `In combination with a conventional drivein theater audio signal distributing system wherein a pair of conductors are used for supplying audio signals from an ampliiier to a plurality of speaker transformers distributed throughout the theater, light means distributed throughout the theater, a source of direct current power, means for connecting sai-d source of direct current power to said distributing system including audio choke means for preventing the flow of audio signals from said system to said source of power, direct current blocking condenser means in said system between said source of power and said amplier for preventing the flow of power from said source to said amplifier, means for connecting said light i means to said system including audio choke means for preventing the flow of audio signals to said light means, and direct current blocking condenser means connected in the circuit leading to each of said speaker transformers for blocking the flow of direct current to the speakers, said light means comprising .incandescent signal lamps.

8. In a drive-in theater, an ampliiier for audio signals, a plurality of loud speaker stations, each of which comprises a transformer having a primary coil and a secondary coil, circuit means for connecting sai-d primary coil to the output of said power amplifier, a plurality of speakers, means for connecting at least one of said speakers to each of said secondary coils, a source of direct current power, means for connecting said direct current power to said circuit means including audio choke coils for preventing the now of audio signals from said amplifier to said power source, blocking condenser means in said circuit means ahead of said amplifierfor preventing the flow of direct current from said power source to said'amplifier, blocking condensers at each of said speaker stations for blocking the" flow of direct currentfrom said power source to said transformers, light means atsaid speaker stations,` means for connecting said `light meansto said transformer output circuit at a point between said last named blocking condensers and said audio choke coils. i

` 9. In a drive-in theater, an amplierfor audio signals,` a pluralitywof` loud speaker stations, each of whichvcomprises a transformer having a primary coil and a secondary coil, circuit means for connecting said primary coil to the output ofsaid power amplifier, a plurality of speakersmeans for connecting at least one of said speakers to each of said secondary coils, a sourceof direct current power, means for connecting said direct current `power to said circuit means including audio choke coils for preventing the flow of audio signals from said amplier to said power source, blocking condenser means in said circuit means ahead of said ampliner` for preventing the flow of direct current from said power source to said amplifier, blocking condensers at each of said speaker stations for blocking the iiow of direct current from said power source to said transformers, light means at said speaker stations, means for connecting said light means to said transformer output circuit at a point between said last named blocking condensers and said audio choke coils, said last named means including audio choke means for preventing the passage of audio signals to said light means.

10. In a drive-in theater, an amplifier for audio signals, a plurality of loud speaker stations, each of which comprises a transformer having a primary coil and a secondary coil, circuit means for connecting said primary coil to the output circuit of said power amplier, a plurality of speakers, means for connecting at least one of said speakers to each of said secondary coils, a source of direct current power. means for connecting said direct current power to said output circuit at a given point including audio choke coils for preventing the flow of audio signals from said amplier to said power source, blocking condenser means in said output circuit between said amplifier and said given point for preventing the flow of direct current from said power source to said amplifier, blocking condensers in said output circuit at each of said speaker stations for blocking the flow of direct current from said power source to said transformers, a plurality of lights at said speaker stations, circuit means for connecting said light to said output circuit in parallel with one another at a point ahead of said last named blocking condensers, and switch means in series with one of said lights for controlling the flow of current to said one light.

11. In a drive-in theater, a power ampliiier for amplifying audio signals, a transformer having a primary coil and a secondary coil, circuit means including a pair of conductors for connecting said primary coil to the output circuit of said power amplifier, a speaker, means for connecting said speaker to said secondary coil, a light means, a source of direct current power, means for connecting said source of direct current powerto said pair of conductors, .said last named means including audio choke means for preventing the'flow of `audio signals from said conductors to said power source, blocking Vcondenser means for preventing the flow of direct current from said power source to said power amplier, means for connecting said light means to said conductors including audio choke means for preventing the flow of audio signals to said light means, and blocking condenser means arranged adjacent said primary coil for blocking` the ow of direct current to said primary coil.

12. In a drive-in theater, a power amplier foramplifying a signal, aplurality of speaker stations, each of which comprises a transformer having a primary coil and a. secondary coil, circuit means for connecting said primary coil to the output of said power amplifier, a source of direct current power, means for connecting said source of power ,to said circuit means in cluding audio choke coils for preventing the ow of audio signals from said circuit means to 20 to each of said secondary coils, a signal light adjacent each of said speakers, means for connecting said signal light to said circuit means ahead of said transformer including an audio choke coil for preventing the ow of audio signals to said signal light, a blocking condenser connected between said transformer and the connections leading to said signal light, and blocking condensers connected in said circuit means between said power amplifier and said source of direct current so as to block the ow of direct current to said power amplifier.

DEMETRIUS G. CHAKIRIS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,463,339 Wetzel et al Mar. 1, 1949 2,469,986 Phyfe -1 May 10, 1949 

